Microsoft introduced an extremely useful feature in their 2005 IDE series. When
hovering over a variable during debugging, you can browse the whole class
hierarchy from within the hover field.

So for instance if you have a class
public class someClass
{
public String str1, str2;
public int int1, int1;
}
declared as 
SomeClass sc = new SomeClass();
sc.str1 = "some string";
sc.str2 = "another string";
sc.int1 = 5;

And you hover over sc, you not only see "SomeClass" but a small + in front of
it, and when you click on it, you get to see the whole class in hierarchic form. 
For more complex hierarchies, you get to see base classes as well, and where the
variables actually belong to.. similar to what you see in "local variable" in
NB, but it's all accessible from within the hover, thus sparing you from having
to open the local variables window (you might not have enough screen real-estate
to always have this open in the size where it gets really useful). 

I'll attach a screenshot that shows how this looks.